Most electrical equipment is powered by electricity supplied by power lines. Mobile telecommunication network equipment is such an example which has large fixed units, such as a base stations and repeaters. Power lines are expensive to install in remote locations and are susceptible to storms and other natural occurrences which can down power lines. Recently in order to reduce the cost of power line installation for electrical equipment located in remote areas, there has been an attempt to use other means of power sources, such as solar cells and windmills. However, neither has proved to be reliable power sources for the same reasons as power lines, as well as other limitations. In order to improve the reliability and reduce the service cost of the electrical equipment in remote locations, other solutions are needed that does not need an external power supply line.
It is an objective of present invention to have electrical equipment in remote locations with an internal power supply.